Journal article

Publication year: 2019

Pages: 2804-2824

Journal: Communications in Soil Science and Plant Analysis

Volume number: 50

Issue number: 22

ISSN: 0010-3624

eISSN: 1532-2416

DOI Link: https://doi.org/10.1080/00103624.2019.1679165

Publisher: Taylor and Francis Group

Abstract: 
Important tools for the investigation of phosphorus (P) in soil are the acid digestion in aqua regia (AR) for total P, the sequential P fractionation (SF), P-31 nuclear magnetic resonance (P-31-NMR) spectroscopy and P K-edge X-ray absorption near-edge structure (P K-edge XANES) spectroscopy. The objective of the present study was to critically compare the outcomes of these methods in order to improve the data evaluation and interpretation. For this purpose, we analyzed total P (P-t) and the P speciation of three groups of soil samples (extremely P-rich, P-poor acidic, P-poor to P-rich alkaline). The recovery of the extracted P between the different methods depended on the soil characteristics, resulting in recommendations for improving the P extraction. The P-31-NMR spectra were calibrated to a monoester standard which provided a better consistency of the peak position in comparison to the shifting of the orthophosphate peak to 6.0 ppm. The SF and P-31-NMR agreed in the inorganic P (P-i) and P-o proportions, especially in the alkaline fraction. The correlation between P-o from P K-edge XANES and diesters from P-31-NMR indicated that P K-edge XANES detected rather diesters than monoesters in soils. Correlations between SF and P K-edge XANES results confirmed the presence of specific P-i species in the sequentially extracted fractions. However, the SF is still relatively unspecific for interpreting P-o species from a certain fraction. A more specific description of the P-o composition in fractions from the SF requires investigation of these fractions by P-31-NMR and P K-edge XANES.

Harvard Citation style: Acksel, A., Baumann, K., Hu, Y. and Leinweber, P. (2019) A critical review and evaluation of some P-research methods, Communications in Soil Science and Plant Analysis, 50(22), pp. 2804-2824. https://doi.org/10.1080/00103624.2019.1679165

APA Citation style: Acksel, A., Baumann, K., Hu, Y., & Leinweber, P. (2019). A critical review and evaluation of some P-research methods. Communications in Soil Science and Plant Analysis. 50(22), 2804-2824. https://doi.org/10.1080/00103624.2019.1679165